content: /*
  Copyright 2006 Jerry Huxtable
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
     http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  */
  
  package com.jhlabs.image;
  
  import java.awt.*;
  import java.awt.image.*;
  
  /**
   * A filter which performs reduces noise by looking at each pixel's 8 neighbours, and if it's a minimum or maximum,
   * replacing it by the next minimum or maximum of the neighbours.
   */
  public class ReduceNoiseFilter extends WholeImageFilter {
  
  	public ReduceNoiseFilter() {
  	}
  
  	private int smooth(int[] v) {
  		int minindex = 0, maxindex = 0, min = Integer.MAX_VALUE, max = Integer.MIN_VALUE;
  		
  		for (int i = 0; i < 9; i++) {
  			if ( i != 4 ) {
  				if (v[i] < min) {
  					min = v[i];
  					minindex = i;
  				}
  				if (v[i] > max) {
  					max = v[i];
  					maxindex = i;
  				}
  			}
  		}
  		if ( v[4] < min )
  			return v[minindex];
  		if ( v[4] > max )
  			return v[maxindex];
  		return v[4];
  	}
  
  	protected int[] filterPixels( int width, int height, int[] inPixels, Rectangle transformedSpace ) {
  		int index = 0;
  		int[] r = new int[9];
  		int[] g = new int[9];
  		int[] b = new int[9];
  		int[] outPixels = new int[width * height];
  
  		for (int y = 0; y < height; y++) {
  			for (int x = 0; x < width; x++) {
  				int k = 0;
  				int irgb = inPixels[index];
  				int ir = (irgb >> 16) & 0xff;
  				int ig = (irgb >> 8) & 0xff;
  				int ib = irgb & 0xff;
  				for (int dy = -1; dy <= 1; dy++) {
  					int iy = y+dy;
  					if (0 <= iy && iy < height) {
  						int ioffset = iy*width;
  						for (int dx = -1; dx <= 1; dx++) {
  							int ix = x+dx;
  							if (0 <= ix && ix < width) {
  								int rgb = inPixels[ioffset+ix];
  								r[k] = (rgb >> 16) & 0xff;
  								g[k] = (rgb >> 8) & 0xff;
  								b[k] = rgb & 0xff;
  							} else {
  								r[k] = ir;
  								g[k] = ig;
  								b[k] = ib;
  							}
  							k++;
  						}
  					} else {
  						for (int dx = -1; dx <= 1; dx++) {
  							r[k] = ir;
  							g[k] = ig;
  							b[k] = ib;
  							k++;
  						}
  					}
  				}
  				outPixels[index] = (inPixels[index] & 0xff000000) | (smooth(r) << 16) | (smooth(g) << 8) | smooth(b);
  				index++;
  			}
  		}
  		return outPixels;
  	}
  
  	public String toString() {
  		return "Blur/Smooth";
  	}
  
  }
  
  